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  • ROBERT KRULWICH: Hi, I'm Robert Krulwich, and welcome to NOVA ScienceNOW, where we consider

  • not one, but several science stories. Tonight, they're basically puzzles beginning with a

  • problem, so just...

  • Come on back. Come on back and...all right, stop. Good. The internal combustion engine,

  • which fouls the air and uses gas which comes from oilówhich is getting expensive, involves

  • the Middle East, gets us into all kinds of fightsówho wouldn't want to replace this

  • with a more efficient and affordable alternative?

  • But is there an alternative?

  • Well, there is this engine we keep hearing about which is supposed to be fabulous. It's

  • coming "soon." But the puzzle is, how soon?

  • Every year, Detroit unveils, with much to do, a "Car of the Future." And the hoopla

  • here isn't about what this car does. It's about what this car doesn't do. This car doesn't

  • use gasoline, none, because it is powered by a fuel cell.

  • GEORGE W. BUSH (President of the United States, 2001- ): Fuel cells...

  • NEWS ANCHOR : ...fuel cells.

  • NEWS CORRESPONDENT: ...powered by a fuel cell.

  • GEORGE W. BUSH: Fuel cells are the wave of the future.

  • NEWS CORRESPONDENT:The wave of the future.

  • ROBERT KRULWICH: Really? This is the future? Well maybe we should take a closer look.

  • So I decided to test drive a fuel-cell car, and I invited a couple of friends to come

  • along.

  • What do we think?

  • TOM MAGLIOZZI: We don't know anything.

  • ROBERT KRULWICH: Tom and Ray Magliozzi, the Car Talk guys from National Public Radio.

  • RAY MAGLIOZZI: What was that whistling noise?

  • ROBERT KRULWICH: Yeah, what is that whistling?

  • RAY MAGLIOZZI: What's that about?

  • ROBERT KRULWICH: Mmmmmm.

  • TOM MAGLIOZZI: That sounds like F above middle C. I would like to open the hood just to see

  • what's there. Don't shut it off.

  • RAY MAGLIOZZI: And don't lock the keys in it. I'll leave a window open. I'm dying to

  • see what's under here.

  • TOM MAGLIOZZI: What the heck is this? See, I knew it. It's not an engine!

  • ROBERT KRULWICH: Well, it has a box, and it has lots of things connecting to it.

  • RAY MAGLIOZZI: Yeah, my intuition tells me this is an electric motor.

  • TOM MAGLIOZZI: This is basically an electric car.

  • RAY MAGLIOZZI: You know what it sounds like? It sounds like my Norge refrigerator used

  • to sound.

  • ROBERT KRULWICH: Tom and Ray know a lot about regular cars, the ones with internal combustion

  • engines.

  • This, on the other hand, is an electric car. But you don't plug it in, instead, it's powered

  • by this mysterious fuel cell thing.

  • RAY MAGLIOZZI: This is stuff, this is technology that none of us understands.

  • TOM MAGLIOZZI: No one told us this.

  • RAY MAGLIOZZI: Do we need help? We need help.

  • ROBERT KRULWICH: Maybe we should ask...

  • RAY MAGLIOZZI: We need someone, a passerby, just some ordinary citizen.

  • ROBERT KRULWICH: Dan.

  • TOM MAGLIOZZI: Who?

  • ROBERT KRULWICH: Oh, my god. Thank goodness the car comes with its own expert, Dan Kelly,

  • who works for a company that actually makes fuel cells.

  • RAY MAGLIOZZI: So it has an electric motor. What runs the motor?

  • DAN KELLY: All the electricity comes from the fuel cell. And the fuel cell is really

  • made up of a collection of these.

  • ROBERT KRULWICH: This is a fuel cell? It looks like a black plastic license plate.

  • DAN KELLY: This is one cell. And it's like a sandwich; you just stack them up. You want

  • more power, add more cells. Make a bigger sandwich. And what goes through, if you look

  • at it...

  • RAY MAGLIOZZI: It's a piece of plastic!

  • DAN KELLY: ...and the grooves that are in it...

  • ROBERT KRULWICH: Yeah, what is this?

  • DAN KELLY: ...you get...Hydrogen runs through these grooves.

  • ROBERT KRULWICH: So what's really going on inside these little holes? How is this thing

  • making electricity?

  • Well, inside the fuel cell, there are two sets of tiny passageways separated by a membrane.

  • And if you look very close, the two main sections are kind of like the two sides of a tennis

  • court. On one side is hydrogen and on the other side oxygen, and then there's the membrane

  • that separates them. It's kind of like a net.

  • So here we are in a tennis court. I, of course, you'll notice now, represent the atom oxygen,

  • and for those of you who are oxygen atoms yourselves, you'll, of course, recognize that

  • I have eight electrons. This is a fuel cell, so oxygen is opposite hydrogen. There are

  • two hydrogen atoms, and if you'll rotate please, you'll see that they too each have one electron.

  • Now it is in the nature of this kind of chemistry that hydrogen and oxygen are attracted to

  • each other.

  • RAY MAGLIOZZI: I yearn for you, Robert.

  • ROBERT KRULWICH: You yearn for me, but there is a membrane between us. Now the rules of

  • the fuel cell are you will try to come to meótry to come to meóbut you'll have to

  • go under or through the membrane. Try under the membrane.

  • TOM MAGLIOZZI: Try under. Okay.

  • ROBERT KRULWICH: Down they go, the two hydrogen atoms approaching the oxygen with ardor, but

  • notice now...

  • TOM MAGLIOZZI: We can do it! Robert, I love you!

  • ROBERT KRULWICH: ...through the membrane...

  • TOM MAGLIOZZI: We made it, Robert! We made it! Oh, my god, finally.

  • ROBERT KRULWICH: Now, butóand I use the word "but" advisedlyócould you please rotate?

  • So show the audience your butts at this moment. You'll notice that this has got no electron;

  • no electron here. The question has to be asked, "Where are the electrons?"

  • Remember when the hydrogen had to come through the membrane? Well, when it did that, its

  • electrons were stripped off. Electrons simply aren't allowed through the membrane in a fuel

  • cell.

  • But they do want to come to the other side. So very cleverly, they go around the membrane,

  • right at the edge of the fuel cell, over and over and over again. And moving electrons,

  • well, that's electrical current. That's what lights up a light bulb, or, in this case,

  • what powers your car.

  • And here's what makes the fuel cells so clean: after the electrons get to the other side,

  • they rejoin their old friends, hook up with the oxygen, and before you know it, you've

  • got H2Oówaterópretty neat.

  • So in these cars, when you check the tailpipe, instead of exhaust, what you get...

  • RAY MAGLIOZZI: ...is water.

  • ROBERT KRULWICH: Oh, how do you know?

  • RAY MAGLIOZZI: 'Cause it looks like water.

  • TOM MAGLIOZZI: Take a drink. Lick it. Lick it!

  • He's dead! I didn't like him anyway.

  • ROBERT KRULWICH: The very idea that a car's motor could be this clean has an enormous

  • appeal, especially to certain politicians. They act like it's going to be easyówell,

  • sometimes they doóbut as it turns out, there's a catch, actually, a bunch of catches. Fuel

  • cells are still very expensive to make, they wear out more quickly. And, oh, yeah, there's

  • another thing...

  • DANIEL NOCERA (Massachusetts Institute of Technology): A fuel cell needs fuel, so we've

  • been talking about hydrogen and oxygen as our fuel. There's lots of oxygen. But where

  • are we going to get the hydrogen in the first place?

  • ROBERT KRULWICH: MIT chemistry professor, Dan Nocera, says, "Remember, you've got to

  • have pure hydrogen, all by itself, on one side of the membrane to get things going."

  • So where do you get pure hydrogen? Well, there's plenty of hydrogen on earth; it's just not

  • pure. It's stuck to other stuff, like oxygen, in water, of course. And hydrogen can be found

  • in fuels like natural gas, you know, hydrocarbons.

  • But if you take it out of thereóand that's where most hydrogen comes from todayóyou

  • do get a waste product, carbon dioxide. And that's one of the bad guys in global warming.

  • So what's the answer?

  • DANIEL NOCERA: I think water is the key for the future.

  • ROBERT KRULWICH: Every high school chemistry student knows how to split water into hydrogen

  • and oxygen. You just run electricity through it. That's electrolysis.

  • But hydrogen and oxygen are so cozy and comfortable together, you use up so much electricity prying

  • them apart, it could cost a fortune. So we are facing a significant technical problem

  • here: how do we find a cheap, clean source of hydrogen?

  • Oh, and there is another issue...

  • RAY MAGLIOZZI: Excuse us for a minute.

  • TOM MAGLIOZZI: We'll be right back.

  • ROBERT KRULWICH: Yeah. Don't we worry a little bit about the danger problem?

  • RAY MAGLIOZZI: What about the Hindenburg?

  • ROBERT KRULWICH: Yeah, what about the Hinden...the huge balloon the Germans...

  • RAY MAGLIOZZI: Yeah. Oh, the humanity...the whole thing.

  • TOM MAGLIOZZI: We've got to ask him.

  • RAY MAGLIOZZI: Yeah, Come on.

  • TOM MAGLIOZZI: Dan...

  • RAY MAGLIOZZI: What about the Hindenburg? Remember the Hindenburg?

  • TOM MAGLIOZZI: Yeah, what about the Hindenburg? Yeah.

  • DAN KELLY: The Hindenburg?

  • ROBERT KRULWICH: The Hindenburg pretty much ruined hydrogen's reputation. But after the

  • explosion, the fire here, the continuous flames that you see, some say they came from the

  • canvas blimp which was coated with highly flammable shellac.

  • DAN KELLY: Are you comfortable getting back in now?

  • RAY MAGLIOZZI: Not really, no. I'll be walking back.

  • ROBERT KRULWICH: One moment, one moment.

  • Of course, gasoline is flammable, too, and we drive around with gallons of that in our

  • cars.

  • It's something else about hydrogen...

  • NATHAN LEWIS (California Institute of Technology): Well, hydrogen's a gas.

  • ROBERT KRULWICH: Okay, so?

  • NATHAN LEWIS: That means most of the space between the hydrogen molecules is not useful

  • to make energy. There's nothing there.

  • ROBERT KRULWICH: So says Nate Lewis, a scientist at Caltech.

  • Getting enough hydrogen into a car is a challenge, because it likes to spread out, and you've

  • got to squeeze a lot of it into a small place.

  • You can't use an ordinary gas tank to hold it, because it would burst open. And you wouldn't

  • want that.

  • Did I run a stop sign?

  • RAY MAGLIOZZI: Noooooooo.

  • ROBERT KRULWICH: No? All right.

  • So the hydrogen tanks have to be super strong, to hold hydrogen squeezed in at pressures

  • up to five to ten thousand pounds per square inch. But even with that special tank, it's

  • tough to get enough hydrogen in the car. For instance, to drive 300 miles, you might need

  • a gas tank four times the size of the one you've got now.

  • Which leads Professor Lewis to suggest the best place for hydrogen fuel might be in power

  • stations, to light up cities and factories.

  • After all, why rush to put this fuel out on the road, when you can easily store plenty

  • of it in a factory basement?

  • So you're a put-it-in-the-basement guy?

  • NATHAN LEWIS: Put it in the basement first. And then, if we ever figure out how to use

  • it to move us around, that will be great. But your car is the last place that you want

  • to put hydrogen.

  • ROBERT KRULWICH: But the dream of a car that spews out nothing but water is so appealing.

  • And if we could use water to fuel the car, that would be even better.

  • TOM MAGLIOZZI: When the technology is really there, you'll be able to open up that little

  • gas fill and fill it up with water like my brother used to do when he was a kid.

  • DAN KELLY: Yeah. So the car will run...

  • ROBERT KRULWICH: But the technology to get hydrogen from water efficiently and affordably?

  • That technology doesn't exist yet.

  • Well, is there anything that we know of that does this regularly, that breaks apart water

  • and...?

  • DANIEL NOCERA: We do. It's the leaf.

  • ROBERT KRULWICH: The, the what?

  • DANIEL NOCERA: Leaf.

  • ROBERT KRULWICH: The leaf. It turns out the leaf is a pro at splitting water. In photosynthesis,

  • leaves take water and break it down. The oxygen goes into the airóthank goodness, because

  • that's what we breatheóand the hydrogen hooks up with carbon to make carbohydrates, which

  • the plant needs for fuel. And the energy to do all this comes from the sun.

  • So does Dan Nocera want to "make like a leaf?"

  • DANIEL NOCERA: So what we've been doing is trying to actually, not duplicate what a leaf

  • does, but we're saying, "Can we generate hydrogen and oxygen by entirely new ways?"

  • ROBERT KRULWICH: In his lab, lasers stand in for the sun.

  • DANIEL NOCERA: What we do is we bring this laser beam in, and now you see, actually,

  • here's a compound that's capturing that green light.

  • ROBERT KRULWICH: So this is your version of sunshine, and this is your version of something

  • that sunshine is acting on?

  • The laser shoots through a liquid mixture concocted in Nocera's lab. He's trying to

  • design a chemical, something like this pink peapod thing, that does a special trick, so

  • when light hits it, it will pull apart the H from the O.

  • Have you ever taken a droplet of water and found a way to just release hydrogen?

  • DANIEL NOCERA: We haven't done water, but we've done hydrochloric acid and we've been

  • able to make hydrogen.

  • ROBERT KRULWICH: So that's a "no." But there are labs all over the country now working

  • on hydrogen. Some work with algae, some with solar collectors. And these guys are making

  • hydrogen from water and sunlight.

  • But at least for now, it's very expensive. And just last year, the National Academy of

  • Engineering and the National Research Council reported there are "major hurdles" on the

  • path to a hydrogen economy, and that clearing them "will not be simple."

  • So even though the President is saying we could have hydrogen cars for today's generation...

  • GEORGE W. BUSH: The first car driven by a child born today could be powered by hydrogen

  • and pollution-free.

  • ROBERT KRULWICH: If the car's really going to be pollution-free, the hydrogen in the

  • tank will have to come from a clean source, and so far, when it comes to splitting water,

  • we're way behind the leaf.

  • Dan and other scientists are trying to catch up and will keep trying, but the secret, he

  • thinks, may be very subtle.

  • So how long did it take for the leaf to figure out how to separate hydrogen from oxygen?

  • DANIEL NOCERA: That took between two and four billion years.

  • ROBERT KRULWICH: But how much time do you have?

  • DANIEL NOCERA: I'm guessing around 20 more years.

  • ROBERT KRULWICH: And so, whatever the politicians may say, learning to "make like a leaf" could

  • take a while.

  • Okay, so we do have time then for a very short puzzle? This one lasts fifty seconds, exactly,

  • unless, of course, you happened to guess the answer earlier.

  • MAN: The key ingredient of this substance was originally extracted from the sapodilla

  • tree. Nowadays, the formulation is coated with fine particles of sucrose and enclosed

  • by a thin layer of aluminum seven microns thick. It contains synthetic materials blended

  • with natural products, such as leche caspi and masuranduba. On contact with the enzyme

  • amylase, secreted by glands in the buckle cavity, its texture is transformed to a malleable

  • compound with elastic properties. After several minutes grinding in a heterodont interface,

  • oral fatigue often leads to removal of the sticky molecular structure and adhesion to

  • a suitable surface.

  • ROBERT KRULWICH: Well, if you got that one, we do have another one at the end of program.

  • It involves a filter-feeding sedentary metazoan. We think you'll probably want to stick around

  • for that.

ROBERT KRULWICH: Hi, I'm Robert Krulwich, and welcome to NOVA ScienceNOW, where we consider

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